sink slumping delimma
Moderators: Brad Walker, Tony Smith
sink slumping delimma
I recently took Patty Grays sink class. The mold we recieved is 19 in ID across, 9 3/4 deep. I do not have a kiln big enough to do the slumping. The local glass blower has offered the use of hers if either one will work. Options are, annealing kiln, side elements three sides, big enough to hold aleast two of these molds. The other is a Paragon 24 ADTSD, which would give me an approximate 3 1/2to 4in. top clearance, and about an inch on the sides. So due too the closeness, or lack of top elements with the annealing kiln, can the slumping process be done in either, and if so I have no idea of a descent slumping schedule. Would be slumping 3/4 float, 15 circle. Thanks Mike
-
Bert Weiss
- Posts: 2339
- Joined: Tue Mar 11, 2003 12:06 am
- Location: Chatham NH
- Contact:
Mike
You have a difficult situation. 1" is very close to the elements on a side fire. You will have to heat up very slowly. Elements on 3 sides is a terrible setup for trying to get glass to slump evenly. Annealers are simply designed to drop in temp, not form glass.
The one thing you do have going for you is that once the glass has slumped you probably have at least 2" from the elements so you have a shot at annealing.
I am not real confident these days about how much time it takes to anneal 3/4" float glass. I have my conservative schedule and my fast schedule. I have been using the fast schedule after the initial fuse and the conservative one after the slump. I haven't yet tried fast on both.
My schedules are figured differently than most of you, who use Bartlett Controllers. I don't have the Bartlett schedules in my head. My conservative schedule soaks at 1000ºF for 8 hours and takes 8 hours to drop to 900, then 6 hours to 700, then 6 hours to 300. Sometimes I shorten the anneal soak. Off the top of my head I forget if my fast schedule is 1/2 or 3/4 the conservative one.
Stone soaks at 1030 for 1 hour 15 minutes, then takes 7 hr 50 minutes to drop to 920, 3 hours 20 minutes to 830, 5 hr 10 minutes to 130.
Thinking about the comparison here, I'd soak for 4.8 hours at 1000 take 4.8 hours down to 900, 3.6 hour to 700, 3.6 hours to 300. I'll try this for both firings at my next class.
My theory is to spend more time soaking at a lower temp and then that same amount of time to ramp down 100º. This approach was approved by Dan Schwoerer and Ray Alghren when I asked them about my appoach verses Graham's.
You have a difficult situation. 1" is very close to the elements on a side fire. You will have to heat up very slowly. Elements on 3 sides is a terrible setup for trying to get glass to slump evenly. Annealers are simply designed to drop in temp, not form glass.
The one thing you do have going for you is that once the glass has slumped you probably have at least 2" from the elements so you have a shot at annealing.
I am not real confident these days about how much time it takes to anneal 3/4" float glass. I have my conservative schedule and my fast schedule. I have been using the fast schedule after the initial fuse and the conservative one after the slump. I haven't yet tried fast on both.
My schedules are figured differently than most of you, who use Bartlett Controllers. I don't have the Bartlett schedules in my head. My conservative schedule soaks at 1000ºF for 8 hours and takes 8 hours to drop to 900, then 6 hours to 700, then 6 hours to 300. Sometimes I shorten the anneal soak. Off the top of my head I forget if my fast schedule is 1/2 or 3/4 the conservative one.
Stone soaks at 1030 for 1 hour 15 minutes, then takes 7 hr 50 minutes to drop to 920, 3 hours 20 minutes to 830, 5 hr 10 minutes to 130.
Thinking about the comparison here, I'd soak for 4.8 hours at 1000 take 4.8 hours down to 900, 3.6 hour to 700, 3.6 hours to 300. I'll try this for both firings at my next class.
My theory is to spend more time soaking at a lower temp and then that same amount of time to ramp down 100º. This approach was approved by Dan Schwoerer and Ray Alghren when I asked them about my appoach verses Graham's.
Bert
Bert Weiss Art Glass*
http://www.customartglass.com
Furniture Lighting Sculpture Tableware
Architectural Commissions
Bert Weiss Art Glass*
http://www.customartglass.com
Furniture Lighting Sculpture Tableware
Architectural Commissions